The present invention relates generally to a casting bench for the molding of vitreous china sanitary fixtures, having complicated shapes, such as toilet bowls, water closets, and bidets.
These fixtures are formed in hygroscopic molds, generally fabricated of plaster or a suitable resin, composed of several complementary parts. The molds typically comprise at least three parts, two of them paired to form a cavity and at least one capable of entering the cavity to create the space in which the fixture is formed.
The molds are used in sets, in which case each of the two paired parts forming the mold has two half-cavities on its opposed faces, so as to create, with two identical parts placed on their sides, two complete forming cavities. Into these complete forming cavities, the third part of the mold, also known as the tool or mandrel, is inserted from above, and possibly a fourth part, known as the foot, is inserted from below.
The most troublesome operation to be performed in the process of casting is the step of de-molding which entails detaching the mold from the casting. This step must be performed with great care so as not to damage the casting, which is still soft and quite fragile. The operation of de-molding has been heretofore performed manually, with a great expenditure of labor.
Thus, it is apparent that an improved method of de-molding is desired which reduces time and labor and it is important that the method be automated.